Roofing Contractor in Pomona, CA: Roofs Built for Valley Heat and Storms

Concrete tile can last 50 years or more, but the felt underlayment beneath it is what actually keeps water out. Once that felt dries, cracks or tears, rain that gets past the tiles goes straight to the roof deck, even though the tiles still look fine.

Phillips Ranch and other tracts from the 1970s and 80s were roofed with concrete tile over standard felt. That felt is now 35–50 years old and has been through decades of summer heat over 100°F. Wherever a tile has cracked or slipped, UV has also been hitting the felt directly. Heavy atmospheric-river rain after a long dry spell finds every weak spot. Homeowners are often surprised that a roof that looks good from the street is leaking, but the cause is almost always the layer they can't see.

• Ceiling stains after the first heavy storm of the season
• Brittle, black felt visible at broken or slipped tiles
• Water stains on attic decking below valleys
• Damp or dark spots on the roof sheathing near eaves
• Musty smell in the attic after rain
• Tiles that rock or have slid out of their rows

This is very common across Phillips Ranch, Diamond Ranch and Ganesha Hills tract homes from the late 1960s through the 1980s. Leaks usually show up first along valleys, at the eaves and around chimneys, and we get most of these calls in the November–January storm weeks.

We remove the tiles, install new high-temperature underlayment and flashing, and then put back the sound original tiles, replacing broken ones with matching tile. This is called a lift-and-relay, and it often costs less than switching to a new roofing material.

Asphalt shingles stay flexible because of the oils in the asphalt. Constant heat drives those oils out, so the shingles lose their granules, curl at the edges, crack and become brittle. A worn-out shingle can no longer shed water or stay put in the wind.

Pomona's inland summers regularly go past 100°F, and the roof surface gets much hotter than that. South- and west-facing slopes get the worst of it, with direct afternoon sun and strong UV almost every day of the year. Many 1940s–60s ranch homes are on their second or third composition roof, and some still have cheap 3-tab shingles from the 1990s. In this climate, shingles often wear out several years before the date printed on the warranty.

• Granules piling up in gutters and downspouts
• Shingle edges curling up or cupping down
• Cracked or split tabs, especially on sunny slopes
• Bare, shiny spots where the granules are gone
• Shingles that crumble when lifted
• Upstairs rooms that get unusually hot in summer

This shows up across the stucco ranch tracts in Westmont, South Pomona, Pomona Heights and the neighborhoods north of Holt Avenue. The south and west slopes usually wear out first, while the north slope of the same roof may still be in fair shape.

If the roof has a few years left, targeted repairs can hold it. Once it's widely brittle, we recommend tearing it off and installing architectural shingles, often in Title 24-compliant cool-roof colors.

Strong, dry winds from the northeast can lift and tear shingles, loosen ridge caps, knock tiles out of place and drive rain under flashing. The damage is often scattered across the roof and hard to see from the ground.

Santa Ana winds blow through the inland valleys every fall and winter, and Pomona sits right in their path. Gusts work on sealant strips that summer heat has already weakened and on tiles held by aging fasteners. The winds often arrive just before the rainy season, so a missing ridge cap or a lifted shingle goes unnoticed until the first storm puts water through the opening. Some wind damage may be covered by homeowners insurance if it's documented properly.

• Shingles or tile pieces in the yard after a wind event
• Missing or loose ridge and hip caps
• Creased shingles with a visible fold line
• Tiles slipped out of their courses
• Lifted flashing at walls and chimneys
• New leaks appearing during wind-driven rain

Exposed hillside homes in Phillips Ranch, Ganesha Hills and Diamond Ranch get hit hardest, along with taller buildings in North Pomona near the Fairplex. Ridge caps and the rakes at gable ends are the most common failure points.

We secure or replace damaged shingles, ridge caps and tiles, reseal the flashing and photograph everything. If you're filing an insurance claim, you can use those photos as documentation.

Low-slope roofs need to drain within about 48 hours of rain. When water sits on the roof, it breaks down the membrane, and it eventually finds its way into the building at parapet wall flashings, scuppers and seams.

Spanish Colonial and Mission Revival homes from the 1920s and 30s often have flat sections hidden behind parapet walls. Pomona's duplexes, garden apartments and commercial buildings use built-up, modified-bitumen and TPO roofs. Years of dust and debris from the dry season clog scuppers and drains, and old built-up roofs sag over time. When an intense winter storm dumps several inches of rain, water backs up against the parapets and gets in through cracked stucco and failed wall flashing.

• Standing water on the roof a day or two after rain
• Alligatored or blistered roof surface
• Stains below parapet walls inside the home
• Cracked stucco along the top of parapets
• Clogged or rusted scuppers and downspouts
• Membrane seams pulling apart

We see this all the time on Spanish Revival homes in Lincoln Park and Hacienda Park, on apartment buildings near Cal Poly Pomona, and on commercial roofs along Holt Avenue, Mission Boulevard and Garey Avenue.

We clear the drains, redo the parapet and scupper flashing, and patch or recover the membrane. If the roof has failed, we replace it with modified bitumen or TPO built with tapered insulation so water drains off.

Tiles crack when people walk on them, when objects hit them, when they expand and contract with heat, and when the ground shakes. Fasteners can also corrode and let tiles slide. Each broken tile exposes the underlayment beneath it to sun and rain.

Pomona sits near the Chino, San Jose and Sierra Madre faults, so even moderate earthquakes can crack or shift heavy tile. Wide temperature swings stress older clay barrel tile, and solar installers and other trades often crack tiles walking across the roof. Historic clay tile in particular can be hard to match. On homes in historic districts, replacement tiles may need to be compatible with the originals.

• Visible cracks or missing tile corners
• Tiles sitting crooked or out of line
• Gaps where tiles have slipped downslope
• Broken tile pieces in gutters
• Leaks after solar or satellite installation
• Underlayment showing through gaps

This is common on Spanish Revival homes downtown and in the Arts Colony, on Phillips Ranch concrete tile, and on any roof that has had solar panels added. We often see it after earthquakes and after other trades have worked on the roof.

We replace broken tiles with matching profiles, reset the ones that have slipped and fasten them properly. We also check the underlayment underneath so we're not covering up a bigger problem.

Rubber pipe collars, sealants, chimney and wall flashing, and old skylight seals all break down in strong sun. Once they crack, water runs into the house at the roof's penetrations even when the roofing material itself is still in good shape.

Pomona gets strong UV almost every day of the year, and rubber and sealants can't hold up to that for long. Many homes still have skylights from the 1970s and 80s with cloudy lenses and failing curbs. With 6–8 dry months each year, a cracked boot won't drip until a heavy storm hits, so these leaks seem to appear out of nowhere.

• Cracked rubber around plumbing vent pipes
• Drips around skylight frames
• Stains around chimneys or furnace flues
• Gaps in caulked flashing joints
• Rusted or bent metal flashing
• Yellowed or crazed skylight lenses

This is common on ranch homes throughout Pomona Heights, Westmont and Palomares Park, and on any house with an original skylight. It's often the cause behind a single isolated leak on an otherwise healthy roof.

We replace the boots with UV-resistant collars and re-flash chimneys and walls. Failing skylights get swapped for modern units with new curbs and flashing.

This is water coming into the house during a storm, or a section of roof torn open by wind or a fallen limb. It calls for a fast temporary fix to protect ceilings, insulation, wiring and belongings while a permanent repair is planned.

Pomona's rain comes in a few intense storms, and that's when every dried-out boot, failed underlayment patch and clogged valley gets tested at once. Emergency calls spike during the first big storm of the season, and everyone needs help the same week. Atmospheric rivers can bring several inches of rain in a day or two, so a small drip can turn into a soaked ceiling quickly.

• Water dripping through ceiling or light fixtures
• Sagging or bubbling drywall
• Wet insulation in the attic
• Visible holes or torn roofing
• Water running down interior walls
• Electrical outlets near water stains

Leaks happen citywide in the first storms from November through February. Older Craftsman and Victorian homes in Lincoln Park and Wilton Heights, and tile roofs in Phillips Ranch, tend to be the hardest hit.

We tarp or seal the opening to stop the water, document the damage, and come back once conditions allow to make a permanent repair or plan a replacement.